Batching, Mixing and Transporting Concrete (Lectures 7)

Question 1

How do we ensure uniformity in batching for concrete mix?

Answer 1

Batching by weight

Question 2

How long should we mix a concrete mixture?

Answer 2

1-3 minutes to obtain uniform mix

Question 3

What are the different ways concrete can be batched, mixed and transported.

Answer 3

Central mixed: Mixed completely in a stationary mixer
Shrink mixed: Mixed partially in stationary mixer, partially in truck
Truck mixed: Mixed completely in truck mixer

Question 4

What are different ways to transport concrete?

Answer 4

Mixer Truck
Special dump trunk
bucket
buggy

Question 5

What is a false set?

Answer 5

Stiffening of concrete shortly after mixing with no generation of heat.

Question 6

What causes a false set?

Answer 6

Improper composition of cement or rehydration of cement

Question 7

What do we do if concrete is false set?

Answer 7

Plasticity can be restored by rigorous mixing

Question 8

How can a false set be prevented

Answer 8

Longer mixing time